Lake Lure Sewer System Replacement and Renovation Overview and Update

Lake Lure Sewer System Replacement Project: Overview and Update

The Town of Lake Lure is undertaking a major infrastructure initiative to replace and renovate its aging sewer system and wastewater treatment plant. This project addresses serious concerns with system reliability, environmental protection, and long-term service sustainability. The following summary outlines the project’s history, current progress, and future plans.

A. Historical Background

Lake Lure’s sewer system, originally constructed in 1927, is a subaqueous gravity-fed system (SASS) that uses submerged pipes to collect and transport sewage under the lake. It is the only system of its kind in North Carolina and one of very few in the United States.

This one-of-a-kind design has served the community for nearly a century, but the cast iron pipes and associated infrastructure have reached the end of their service life.

B. Project Drivers

The original SASS conveys wastewater to a pump station located behind the dam. From there, it is pumped to the wastewater treatment plant (WWTP). Over the years, both facilities have experienced:

• Severe lake water infiltration
• Equipment obsolescence and corrosion
• Increased risk of sewer spills
• An overreliance on chemical treatment processes

These issues have posed a growing threat to public health, environmental quality, and the reliability of the system. These vulnerabilities were further exposed and intensified by Tropical Storm Helene, which devastated Lake Lure on September 27, 2024, causing widespread damage to infrastructure and accelerating the need for system-wide replacement and upgrades.

C. Engineering Evaluation and Initial Planning

In February 2020, the Town engaged LaBella Associates to evaluate twelve potential alternatives for replacing the aging sewer system. The objective was to identify a sustainable and modern solution that could be implemented in phases while maintaining uninterrupted sewer service.

The Town selected a phased replacement strategy that transitions away from the submerged system. The new plan involves installing a perimeter sewer system along the lake’s back-shore, which is the area of land exposed during scheduled lake draw downs.

D. Phase 1 Construction and Challenges

Construction of Phase 1 began in 2023 in the Sunset Cove area. The initial method involved boring pipe sleeves under boathouses within the back-shore. However, this phase faced several major setbacks:

• Delays due to weather and conflicts with drain valve installation project
• Unforeseen difficulty in back-shore heavy construction work
• Less progress than anticipated despite significant investment

Due to these challenges, the Town paused further implementation of this approach and has secured North Carolina Department of Environmental Quality (NCDEQ) approval of a more viable and cost-effective construction strategy that will continue to follow the original plan of utilizing the back-shore area.

E. Updated Project Strategy

The Town continues to collaborate with NCDEQ, including the Division of Water Resources and the Division of Water Infrastructure, to revise the project design. The updated approach retains the use of the lake perimeter and backshore areas in order to minimize private property impacts, but incorporates lessons learned from Phase 1 to ensure future phases are efficient and feasible.

LaBella Associates remains the Town’s engineering consultant and is leading efforts to finalize the revised design.

F. Sewer Access Valve and Lake Drawdowns

To support construction and improve emergency preparedness, the Town completed installation of a new sewer access valve (also referred to as the reservoir drain valve) in March 2025. This key improvement allows the lake to be safely lowered below the spillway and provides the following benefits:

• Enables future construction of underwater infrastructure
• Enhances emergency response in case of dam failure or system collapse
• Increases control over lake levels during critical work windows

2022–2023 Drawdown Activities

In July 2022, Town Council finalized plans for the 2022–2023 lake drawdown. The lake was lowered beginning January 1, 2023, and began refilling on March 31, 2023.

Projects completed or initiated during this drawdown included:

• Beginning of Phase 1 sewer system replacement in Sunset Cove
• Lake dredging with excavators
• Seawall repairs and replacements
• Penstock inspections and warranty repairs
• Installation of the sewer access valve

Lake levels ranged between five and twelve feet below full pond depending on project needs.

G. Wastewater Treatment Plant (WWTP) Replacement

Originally, Phase 1 included temporary renovations to the existing WWTP to keep it operational until a full system upgrade could be completed. However, Tropical Storm Helene caused severe damage to the WWTP, making permanent repairs unfeasible.

The Town is currently pursuing FEMA funding to support the construction of a new wastewater treatment facility. Town Council has authorized LaBella Associates to begin design work once federal funding is secured. In preparation for this project, the Town acquired property outside of the floodplain in 2024, which will serve as the site for the new WWTP.

The future facility will incorporate a modern biological treatment process capable of meeting all current water quality standards.

H. Manhole Rehabilitation

During the 2021–2022 drawdown, the Town completed rehabilitation of existing manholes throughout the sewer system. This work:

• Reduced infiltration of lake water
• Extended the useful life of the manholes
• Improved performance at the WWTP
• Prepared infrastructure for future system connections

Unfortunately, many of these improvements were compromised by the impacts of Tropical Storm Helene, which caused significant damage to the area and disrupted the recent infrastructure upgrades.

I. Final System Design and Benefits

The newly-approved SASS Replacement Project replaces the existing Lake perimeter manholes (where customers are currently connected) with Pump Stations, and replaces the Lake-bottom gravity sewers with force mains.  Key system components include:

• Long-life high-density polyethylene (HDPE) sewer lines
• HDPE pump stations surrounded by small shoreline decks.

This updated system will:

• Provide reliable, modern sewer service to all properties
• Minimize property and environmental disruptions
• Extend access to areas not currently well-served
• Support renovations and additions to lakefront homes
• Enable functionality of a new WWTP
• Improve year-round maintenance and operations for the Town

This option was determined to have the lowest total environmental, social, and economic cost of all the alternatives considered.

J. Community Engagement

The Town Council remains committed to transparency and keeping the public informed throughout the sewer system replacement and renovation project. Public forums and roundtable discussions have been held to share project details and gather feedback from residents. These efforts reflect the Town’s ongoing dedication to open communication and community involvement as the project moves forward.